1. Field of the Invention
The present invention relates to a heat insulation plate mounting structure on a fuel tank, for mounting a heat insulation plate in a predetermined region of a fuel tank made of resin.
2. Description of the Related Art
In recent years, a fuel tank made of resin has been utilized for the vehicles. The tank made of resin has sufficient strength, and has lighter weight than a metallic tank, with an advantage that there is no problem with the occurrence of rust. The tank made of resin is composed of a polyethylene single layer or a multi-layer of polyethylene and other resins in which the outermost layer is at least made of polyethylene.
However, some members of a vehicle such as an engine or a muffler are heated to high temperatures. If they are disposed close to the tank made of resin, there is a danger that the tank is thermally damaged and deformed or pitted-with hole. When the member heated to high temperatures is located near the tank, the heat insulation plate made of a metallic plate is disposed between the tank and the member heated to high temperatures. This heat insulation plate is curved to the almost same shape as the tank surface, and mounted on the tank with a certain gap.
A conventional structure for mounting this heat insulation plate on the fuel tank is well known in which a bolt is inserted into a barrel member made of polyethylene, with an end portion of the bolt protruding from one end of the barrel member and the other end of the barrel member being welded to the surface of the fuel tank, so that the bolt is fixed to the surface of the fuel tank to mount the heat insulation plate.
However, in the conventional structure for mounting the heat insulation plate on the fuel tank, the barrel member made of polyethylene has a relatively low melting point and is weak to heat. Therefore, there was a fear that the barrel member might be deformed due to heat transmitted from the heat insulation plate or bolt, or fall away from the tank surface.